We have an article that explains where to find the update history logs here:
The following article shows how to find errors within the logs:
The following procedure shows how to quickly check the status of previously run updates.
You can get a list of the times and dates when updates ran on the server with the following command:
tail -5 /var/cpanel/updatelogs/summary.log
The following command will provide a list of each update log file name and then the line of the log that shows whether or not the update was completed successfully or not:
find /var/cpanel/updatelogs/* -name "update*" | while read updatelog;do echo $updatelog;grep "Pre Maintenance" $updatelog ;echo;done
If you find that some updates did not complete successfully, check the following article for more information on reviewing the error: